The Clinical Core was founded in 1992 under the auspices of a previous Program Project as the most efficient mechanism for recruiting, evaluating and referring subjects to the Program's human subjects investigations and for establishing and managing a permanent database of clinical, demographic, and psychosocial information on patients and controls for use by the investigators. A biometric section will be incorporated in this core in the upcoming funding period. The core will continue subject management, quarterly contacts with enrolled subjects, and web-based data collection to support the ongoing, longitudinal prospective study of risk factors in the development of TMD (Subproject by Maixner). In addition the core will be responsible for the recruitment of, and database creation and management of subjects participating in all the Pain Mechanisms Studies of Subprojects by Maixner, Hollins, and Essick. Accordingly, the specific aims and function of this core are to: 1. Recruit and confirm a diagnosis for TMD patients, fibromyalgia (FM) patients, and healthy subjects. A phone screening for exclusion criteria will precede a screening visit that will include a medical history and diagnostic physical exam by a health care professional, as well as completion of demographic and health history questionnaires. 2. Coordinate subjects' participation in the human studies by scheduling screening visits and testing sessions in Subprojects by Maixner, Hollins, and Essick; by randomizing subjects to testing protocol, where appropriate; and by monitoring compliance with protocols. 3. For Subproject by Maixner, coordinate randomization and dispensing the beta-adrenergic blockade agent and placebo; and monitor subjects for drug side effects. 4. Oversee data collection, entry, processing, storage, and distribution to the investigators from patients and healthy subjects relevant to their research inquiries. 5. Assist investigators in designing and implementing plans for statistical analyses of research data, and in the interpretation of results.